com.mhuss.AstroLib

Class Lunar

java.lang.Object

com.mhuss.AstroLib.Lunar

public class Lunar
extends java.lang.Object

A class that can calculate lunar fundmentals for any reasonable time.

Based on C code by Bill Gray (www.projectpluto.com)

This class calculates Lunar fundamentals, and also contains some functions which depend on these fundimentals, including latitude, longitude & distance, phase angle and illuminated fraction.

The lunar fundamentals must be calculated before calling most of the functions in this class.

Field Summary

Fields

Modifier and Type	Field and Description
static int	FULL phase constant
static int	NEW phase constant
static int	Q1 phase constant
static int	Q3 phase constant

Constructor Summary

Constructors

Constructor and Description
Lunar() Default constructor
Lunar(double t) Date/time constructor.

Method Summary

Modifier and Type	Method and Description
void	calcAllLEs(LocationElements locs, double t) Calculate the fundamentals and then all three location elements for the given time.
void	calcFundamentals(double t) Calculates the lunar fundamanentals for a given time.
double	getLatitude() Calculate the latitude in degrees.
double	getLatitudeRadians() Calculate the lunar latitude in radians.
double	getLongitude() Calculate the lunar longitude in degrees.
double	getLongitudeRadians() Calculate the lunar longitude in radians.
static double	getPhase(long jd, int quarter) Calculate the time of the quarter nearest the given Julian day.
static double	getPhase(long jd, int quarter, java.util.Calendar cal) Calculate the time of the quarter nearest the given Julian day.
double	getRadius() Calculate the lunar radius (distance).
double	illuminatedFraction() Calculate the illuminated fraction.
static void	main(java.lang.String[] args) (for unit testing only)
double	phaseAngle() Calculate the phase angle in radians.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NEW

public static final int NEW

phase constant

See Also:

Constant Field Values

Q1

public static final int Q1

phase constant

See Also:

Constant Field Values

FULL

public static final int FULL

phase constant

See Also:

Constant Field Values

Q3

public static final int Q3

phase constant

See Also:

Constant Field Values

Constructor Detail

Lunar

public Lunar()

Default constructor

Lunar

public Lunar(double t)

Date/time constructor. This constructor uses the time provided to calculate the lunar fundamentals.

Parameters:

t - Time in Julian centuries ref J2000

Method Detail

calcFundamentals

public void calcFundamentals(double t)

Calculates the lunar fundamanentals for a given time.

Parameters:

t - Time in Julian centuries referenced to J2000

phaseAngle

public double phaseAngle()
                  throws NoInitException

Calculate the phase angle in radians.
(Using Meeus' easy lower precision method).

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The current phase angle in radians

Throws:

NoInitException

illuminatedFraction

public double illuminatedFraction()
                           throws NoInitException

Calculate the illuminated fraction.

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The current illuminated fraction (0.0 to 1.0)

Throws:

NoInitException

getPhase

public static double getPhase(long jd,
                              int quarter,
                              java.util.Calendar cal)

Calculate the time of the quarter nearest the given Julian day.

Parameters:

jd - A Julian day close to the expected date

quarter - (Lunar.NEW, Q1, FULL, or Q3)

cal - Calendar to use for time zone adjustment; if null no time zone adjustment is performed

Returns:

The relatively exact Julian day with decimal

getPhase

public static double getPhase(long jd,
                              int quarter)

Calculate the time of the quarter nearest the given Julian day.

Parameters:

jd - A Julian day close to the expected date

quarter - (Lunar.NEW, Q1, FULL, or Q3)

Returns:

The relatively exact Julian day with decimal

getLatitude

public double getLatitude()
                   throws NoInitException

Calculate the latitude in degrees.

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The latitude in degrees

Throws:

NoInitException

getLatitudeRadians

public double getLatitudeRadians()
                          throws NoInitException

Calculate the lunar latitude in radians.

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The lunar latitude in radians

Throws:

NoInitException

getLongitude

public double getLongitude()
                    throws NoInitException

Calculate the lunar longitude in degrees.

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The lunar longitude in degrees

Throws:

NoInitException

getLongitudeRadians

public double getLongitudeRadians()
                           throws NoInitException

Calculate the lunar longitude in radians.

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The lunar longitude in radians

Throws:

NoInitException

getRadius

public double getRadius()
                 throws NoInitException

Calculate the lunar radius (distance).

NOTE: The lunar fundamentals must be calculated before calling this function or a NoInitException will be thrown.

Returns:

The lunar radius

Throws:

NoInitException

calcAllLEs

public void calcAllLEs(LocationElements locs,
                       double t)
                throws NoInitException

Calculate the fundamentals and then all three location elements for the given time. This function calls callFundamentals().

Parameters:

locs - Where the calculated LEs go

t - time in decimal centuries

Throws:

NoInitException

main

public static void main(java.lang.String[] args)

(for unit testing only)